diff options
Diffstat (limited to 'sysdeps/sparc/sparc64/fpu/s_ceil.S')
| -rw-r--r-- | sysdeps/sparc/sparc64/fpu/s_ceil.S | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/sysdeps/sparc/sparc64/fpu/s_ceil.S b/sysdeps/sparc/sparc64/fpu/s_ceil.S new file mode 100644 index 0000000000..7e9bfef06a --- /dev/null +++ b/sysdeps/sparc/sparc64/fpu/s_ceil.S @@ -0,0 +1,84 @@ +/* ceil function, sparc64 version. + Copyright (C) 2012 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by David S. Miller <davem@davemloft.net>, 2012. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, see + <http://www.gnu.org/licenses/>. */ + +#include <sysdep.h> + + /* Since changing the rounding mode is extremely expensive, we + * try to round up using a method that is rounding mode + * agnostic. + * + * We add then subtract (or subtract than add if the initial + * value was negative) 2**23 to the value, then subtract it + * back out. + * + * This will clear out the fractional portion of the value. + * One of two things will happen for non-whole initial values. + * Either the rounding mode will round it up, or it will be + * rounded down. If the value started out whole, it will be + * equal after the addition and subtraction. This means we + * can accurately detect with one test whether we need to add + * another 1.0 to round it up properly. + * + * We pop constants into the FPU registers using the incoming + * argument stack slots, since this avoid having to use any PIC + * references. We also thus avoid having to allocate a register + * window. + * + * VIS instructions are used to facilitate the formation of + * easier constants, and the propagation of the sign bit. + */ + +#define TWO_FIFTYTWO 0x43300000 /* 2**52 */ +#define ONE_DOT_ZERO 0x3ff00000 /* 1.0 */ + +#define ZERO %f10 /* 0.0 */ +#define SIGN_BIT %f12 /* -0.0 */ + +ENTRY (__ceil) + sethi %hi(TWO_FIFTYTWO), %o2 + sethi %hi(ONE_DOT_ZERO), %o3 + fzero ZERO + + sllx %o2, 32, %o2 + fnegd ZERO, SIGN_BIT + + sllx %o3, 32, %o3 + stx %o2, [%sp + STACK_BIAS + 128] + fabsd %f0, %f14 + + ldd [%sp + STACK_BIAS + 128], %f16 + fcmpd %fcc3, %f14, %f16 + + fmovduge %fcc3, ZERO, %f16 + fand %f0, SIGN_BIT, SIGN_BIT + + for %f16, SIGN_BIT, %f16 + faddd %f0, %f16, %f18 + fsubd %f18, %f16, %f18 + fcmpd %fcc2, %f18, %f0 + stx %o3, [%fp + STACK_BIAS + 128] + + ldd [%fp + STACK_BIAS + 128], %f20 + fmovduge %fcc2, ZERO, %f20 + faddd %f18, %f20, %f0 + fabsd %f0, %f0 + retl + for %f0, SIGN_BIT, %f0 +END (__ceil) +weak_alias (__ceil, ceil) |